口内扫描与锥形束CT重建牙颌数字化模型的测量分析

COMPARISON OF MEASUREMENT BETWEEN THREE-DIMENSIONAL DIGITAL DENTAL MODELS RECONSTRUCTED BY INTRAORAL SCAN AND CONE-BEAM COMPUTED TOMOGRAPHY

目的比较采用口内扫描与锥形束CT(CBCT)两种方法重建的牙颌数字化模型测量结果的差异。方法选取于我院口腔科门诊行智牙拔除的患者12例,通过口内扫描与CBCT分别重建牙颌数字化模型(口内扫描模型、CBCT模型)。采用Mimics 15.01软件在两种模型上分别定点,测量上、下颌牙列所有牙冠的近远中宽度及牙弓宽度。采用SPSS 16.0软件包中的配对t检验、散点图和组内相关系数(ICC)评估两种模型的测量差异。结果两种模型中,上颌第一前磨牙、下颌尖牙、下颌第二磨牙牙冠近远中宽度的测量值间有显著差异(t=-3.302~4.225,P<0.01),余牙牙冠宽度及牙弓宽度的测量值间差异无显著性(P>0.05);两种模型牙冠及牙弓宽度测量值ICC>0.950,上颌前牙牙冠宽度测量值的一致性最好(ICC=0.953)。结论口内扫描模型与CBCT模型存在部分差异,在模型拟合时建议采用尖牙牙尖、第一前磨牙中央窝、第一磨牙中央窝及上颌前牙作为模型配准的参考点。

Objective To investigate the difference between three-dimensional digital dental models reconstructed by intraoral scan and cone-beam computed tomography(CBCT).Methods A total of 12 patients who underwent wisdom tooth extraction at the outpatient service of the Department of Stomatology in our hospital were enrolled.Three-dimensional digital dental models(intraoral scan model and CBCT model)were reconstructed by intraoral scan and CBCT.Mimics 15.01 was used to set points on the two models,and the mesiodistal width of dental crown for all maxillary and mandibular teeth and dental arch width were measured.With SPSS 16.0 software package,the paired t test,scatter plots,and intraclass correlation coefficient(ICC)were used to evaluate the difference between the two models.Results There were significant differences between the two models in their measurement results for the mesiodistal width of dental crown for the maxillary first premolars,mandibular canines,and mandibular second molars width(t=-3.302-4.225,P<0.01).However,there were no significant differences for the dental crown width of other teeth and dental arch width(P>0.05).ICCs of the dental crown width and dental arch width were>0.950 for both models,and the ICC of the dental crown width of maxillary anterior teeth was best(ICC=0.953).Conclusion There are some differences between intraoral scan model and CBCT model.Cusp of canines,fossa of first premolars and first molars,and maxillary anterior teeth are recommended to be used as reference points for model alignment.